Transition condition and control mechanism of subatmospheric flame spread rate over horizontal thin paper sample

Research output: Scientific - peer-reviewArticle

Details

Original languageEnglish
Pages (from-to)90-93
Number of pages4
JournalCombustion and Flame
Volume188
StatePublished - 1 Feb 2018
MoE publication typeA1 Journal article-refereed

Researchers

  • Jun Fang
  • Xuan-ze He
  • Kai-yuan Li
  • Jing-wu Wang
  • Yong-ming Zhang

Research units

  • University of Science and Technology of China
  • Université de Lille

Abstract

The horizontal flame spread over paper samples was investigated using a subatmospheric cabin with varied O2 concentration. The 25 kPa is found to be a clear turning point for the flame illumination and structure, radiative heat flux and flame spread rate (FSR), which leads to the transition boundary between the extinction limits and power law regions. In the extinction limits (non-linear) region below 25 kPa, the oxygen partial pressure is low with a small Da number. Consequently, the flame spread is gas phase kinetics controlled, resulting in low burning rate, low radiative heat loss and weak buoyancy, and thus the FSR is more sensitive to the oxygen concentration while less sensitive to the ambient pressure. In the power law (linear) region above 25 kPa, in contrast, the oxygen partial pressure is high and the Da number is large, and the flame spread is heat transfer controlled, which weakens the dependence of FSR on oxygen concentration and enhances the dependence on air pressure.

ID: 15847043